The present invention relates generally to innovations and improvements in meat blending systems incorporating the continuous X-ray analysis of streams of meat and adjusting for the non-uniformity of such streams. It is especially suitable for use in large-scale formulation of sausage and of ground meat.
Using X-ray beams to determine relative amounts of components within materials, such as the quantity of fat within meat, are known, for example, from Madigan U.S. Pat. No. 2,992,332, herein incorporated by reference, which deals with a device for determining the quantitative relationship between meat components by measuring gamma ray penetration thereof. Developments such as these recognize that lean meat has a high concentration of moisture and protein and includes nitrogen and oxygen atoms which are of a greater atomic number than the carbon and hydrogen atoms which predominate in meat fat, meaning that the lean meat absorbs gamma radiation to a far greater extent than does the fat when the gamma rays are within that range of strength wherein the X-ray energy incident upon the meat is attenuated as a result of a phenomenon known as the photoelectric effect. Devices of the type described in Madigan are limited in their usefulness and accuracy because they require periodic offstream statistical sampling of the meat being analyzed, the samples having to be of uniform predetermined weight, size, and geometrical configuration. They also require a high degree of homogeniety of batches tested which is achieved by time-consuming and capital-intensive mixing at each stage.
Copending U.S. Ser. No. 843,702, filed Oct. 19, 1977 by William H. Groves and Andrew E. Donovan, entitled Two-Level X-Ray Analysis for Determining Fat Percentage, recognizes that beam measurements may be conducted at two different energy levels of polychromatic beams, such as the X-rays generated by Coolidge tubes, to analyze meats for fat content even though the meats analyzed have non-uniform weights and sizes so long as they have relatively smooth surfaces. A copending application of Inge B. Henriksen, entitled Multiple-Level X-Ray Analysis for Determining Fat Percentage, eliminates the need to smooth the meat before analysis if it does not already have a relatively smooth surface by using more than two different energy levels of polychromatic beams. Neither copending application deals specifically with the continuous analysis of streams of meat and adjusting for the non-uniformity of such streams.
Representative of patents describing the blending of meat for the purpose of preparing a meat formulation having a predetermined fat content are Gillespi U.S. Pat. No. 3,851,075; Larsen U.S. Pat. No. 3,734,741; and Kielsmeier, et al. U.S. Pat. No. 3,050,399, but none of these patents indicates that its system has the capability of the present invention of using X-ray beams for continuously analyzing entire flowing meat streams of non-uniform consistency in situ while conducting actual measurements on the meat streams in order to account for the non-uniformity thereof so as to enhance the accuracy of the analysis and the invariability of the blended formulation.
A modification of the device as described in said Madigan U.S. Pat. No. 2,992,332 is known by the trade designation of Model M-401 Continuous Anyl-Ray Meat Analyzer. This Model M-401 is a commercially available component of the present invention which is described in more detail herein. A main objective of the Model M-401 itself is to determine, continuously, the percent fat of a meat pumped through it. Basically, it refines the concepts of the Madigan patent so they can be applied to a flow of meat, rather than to only off-stream samples thereof. For accurate analysis results, the meat must be passing therethrough at a constant rate of flow and be free of voids. This device relies on an assemption that it is continuously measuring a uniform sample of a meat flow, although under actual plant conditions such uniformity is not always easily and efficiently attained.
It is accordingly a general object of the present invention to provide an improved means for continuously determining the fat percentages of streams of meat.
Another object of the present invention is an improved method and apparatus using polychromatic X-ray beams and a sensor to monitor the fat content of streams of meat in a manner that accounts for non-uniformities in the streams.
Another object of this invention is an improved method and apparatus for continuously determining the fat content of streams of meat having variable or non-uniform properties, continuously calculating the amounts of such streams that must be added to arrive at a formulation having a desired weight and a desired percent fat, and automatically blending the streams in the proportions needed to achieve the desired formulation.
Another object of this invention is an improved method and apparatus for accurately, automatically and continuously producing meat blends suitable for forming into meat patties of uniform fat percentages.
Another object of the present invention is an improved method and apparatus for automatically preparing meat batches having a desired weight as well as a desired fat percentage for blending with other weighed sausage ingredients during the continuous preparation of sausage formulations.
Another object of the present invention is an improved method and apparatus for producing meat blends of predetermined fat percentage, either in batches of predetermined weight for sausage formulations and the like or in batches of variable weight for ground meat formulations and the like, which can be operated by relatively unskilled labor and under plant operation conditions.